﻿#region License
// Copyright (c) 2007 James Newton-King
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Collections.Generic;
using System.Net;
using System.Runtime.CompilerServices;
using Lib.JSON.Utilities;

namespace Lib.JSON.Serialization
{
  internal abstract class JsonSerializerInternalBase
  {
    private class ReferenceEqualsEqualityComparer : IEqualityComparer<object>
    {
      bool IEqualityComparer<object>.Equals(object x, object y)
      {
        return ReferenceEquals(x, y);
      }

      int IEqualityComparer<object>.GetHashCode(object obj)
      {
#if !PocketPC
        // put objects in a bucket based on their reference
        return RuntimeHelpers.GetHashCode(obj);
#else
        // put all objects in the same bucket so ReferenceEquals is called on all
        return -1;
#endif
      }
    }

    private ErrorContext _currentErrorContext;
    private BidirectionalDictionary<string, object> _mappings;

    internal readonly JsonSerializer Serializer;

    protected JsonSerializerInternalBase(JsonSerializer serializer)
    {
      ValidationUtils.ArgumentNotNull(serializer, "serializer");

      Serializer = serializer;
    }

    internal BidirectionalDictionary<string, object> DefaultReferenceMappings
    {
      get
      {
        // override equality comparer for object key dictionary
        // object will be modified as it deserializes and might have mutable hashcode
        if (_mappings == null)
          _mappings = new BidirectionalDictionary<string, object>(
            EqualityComparer<string>.Default,
            new ReferenceEqualsEqualityComparer());

        return _mappings;
      }
    }

    protected ErrorContext GetErrorContext(object currentObject, object member, Exception error)
    {
      if (_currentErrorContext == null)
        _currentErrorContext = new ErrorContext(currentObject, member, error);

      if (_currentErrorContext.Error != error)
        throw new InvalidOperationException("Current error context error is different to requested error.");

      return _currentErrorContext;
    }

    protected void ClearErrorContext()
    {
      if (_currentErrorContext == null)
        throw new InvalidOperationException("Could not clear error context. Error context is already null.");

      _currentErrorContext = null;
    }

    protected bool IsErrorHandled(object currentObject, JsonContract contract, object keyValue, Exception ex)
    {
      ErrorContext errorContext = GetErrorContext(currentObject, keyValue, ex);
      contract.InvokeOnError(currentObject, Serializer.Context, errorContext);

      if (!errorContext.Handled)
        Serializer.OnError(new ErrorEventArgs(currentObject, errorContext));

      return errorContext.Handled;
    }
  }
}